METHOD FOR JUDGING INPUT VIDEO SIGNAL AND AUTOMATIC JUDGING CIRCUIT

摘要

PROBLEM TO BE SOLVED: To provide a method for judging an input video signal and judging circuit for automatically judging whether it is inputted from which type of video appliance when the video signal is inputted. ;SOLUTION: A signal input judging circuit 11 detects a synchronizing signal and outputs a detecting signal (b). When receiving the detecting signal (b), an input video signal judging part 12 switches a switch 13 onto a separate signal input side to determine the presence of the next detecting signal (b), and if there is a detecting signal (b), it makes a signal discrimination flag correspond to 'separate' and stopping the judging operation. If there is no detecting signal (b), the judging part 12 switches the switch 13 onto a composite signal input side to determine the presence of the next detecting signal (b). If there is a detecting signal (b), it makes 'composite' correspond to a signal discrimination flag and stopping the judging operation. If there is no detecting signal (b), the judging part 12 switches the switch 13 onto a separate signal input signal to wait the next detecting signal (b).;COPYRIGHT: (C)1998,JPO